Summary Under the proposed Cloud and AI Development Act (CADA), the EU Open Source Solutions Catalogue (EU OSS Catalogue) would be hosted on the Interoperable Europe portal. Specifically, Article 43(2) of the proposal mandates that the catalogue be hosted on the portal "referred to in Article 8 of Regulation (EU) 2024/903" and must be "accessible electronically free of charge." This hosting choice is strategic: as explained in Recital 83, placing the catalogue on this specific portal ensures that solutions can be "easily linked to further relevant information and training." The catalogue acts as a central discovery tool, federating existing national and institutional repositories rather than replacing them, thereby maximizing the reuse of publicly funded software across the Union.

Detail

The proposed Cloud and AI Development Act (CADA), COM(2026) 502 final, establishes a comprehensive framework to strengthen Europe's cloud and AI ecosystem. A critical pillar of this framework is the promotion of open-source software (OSS) to enhance technological sovereignty, security, and interoperability. To achieve this, the proposal creates a centralized discovery mechanism: the EU Open Source Solutions Catalogue.

Legal Basis and Hosting Mandate

The specific location and accessibility of the catalogue are defined in Title IV, Chapter V of the proposal, which focuses on open source. Article 43 sets out the rules for the establishment and maintenance of the EU OSS Catalogue.

1. Hosting Location: The Interoperable Europe Portal Article 43(2) explicitly dictates the hosting infrastructure:

"The EU OSS Catalogue shall be hosted on the Interoperable Europe portal referred to in Article 8 of Regulation (EU) 2024/903 and shall be accessible electronically free of charge."

This provision anchors the new catalogue within the existing legal and technical framework of the Interoperable Europe Act (Regulation (EU) 2024/903). By referencing Article 8 of that Regulation, CADA ensures that the catalogue leverages the established governance, security, and interoperability standards of the Interoperable Europe portal. This avoids the need to build a standalone, siloed platform and instead integrates open-source discovery into the broader EU digital public service infrastructure.

2. Accessibility and Cost The same paragraph mandates that the catalogue be "accessible electronically free of charge." This removes financial barriers to entry, ensuring that any Union entity, public sector body, SME, or developer can access the catalogue without cost. This aligns with the broader CADA objective of fostering a competitive and innovative ecosystem where access to public-sector software is not restricted by licensing fees or paywalls.

3. Federated Architecture: Connecting Existing Repositories The proposal does not intend to centralize the actual storage of code in a single location. Instead, it creates a federated discovery layer. Article 43(3) empowers the Commission to manage the connection of other repositories:

"The Commission shall, on the basis of objective and relevant criteria, decide on the request of any Union entity or public sector body owning or maintaining a catalogue or repository to have that catalogue or repository connected to and made accessible through the EU OSS Catalogue."

This mechanism allows national, regional, or institutional repositories to remain the primary hosts for the software while ensuring they are discoverable via the central EU OSS Catalogue. The Commission acts as the gatekeeper, evaluating requests based on objective criteria to ensure quality and interoperability.

Policy Context and Rationale

The choice of the Interoperable Europe portal is not merely technical; it is deeply rooted in the policy objectives of the proposal. Recital 83 of the explanatory memorandum provides the strategic justification for this hosting arrangement.

The recital notes that software is often made available in different repositories, which "hamper[s] searchability, discoverability and, ultimately, reuse." To solve this, the proposal requires a centralized catalogue. However, the recital goes further to explain why the Interoperable Europe portal is the chosen host:

"Hosting the EU Open Source Solutions Catalogue on the Interoperable Europe portal referred to in Article 8 of Regulation (EU) 2024/903 will ensure that solutions can be easily linked to further relevant information and training."

This linkage is crucial. Open-source adoption often fails not because of the code itself, but because of a lack of context, documentation, or skills. By hosting the catalogue on a portal designed for interoperability and digital public services, CADA ensures that a developer finding a solution can immediately access:

  • Relevant Information: Technical specifications, interoperability profiles, and usage guidelines.
  • Training: Educational resources to help public sector bodies and developers understand how to implement the software.

This integration transforms the catalogue from a simple file repository into a comprehensive ecosystem support tool.

Obligations for Public Sector Bodies

While Article 43 governs the Commission's role in maintaining the central catalogue, Article 42 places obligations on the supply side. Article 42 states:

"When making software to which they hold intellectual property rights available for reuse under an open source licence, a Union entity or public sector body shall do so using a catalogue or repository that is connected to, and made accessible through, the EU OSS Catalogue."

This creates a closed loop: public bodies must use a connected repository to publish their software, and the Commission must ensure the central catalogue connects to those repositories. This ensures that the "one-stop-shop" vision is realized without forcing every public body to migrate its existing infrastructure.

What this means for you

For technology leaders, open-source maintainers, and public-sector IT managers, the hosting of the EU OSS Catalogue on the Interoperable Europe portal has specific, actionable implications under the proposed CADA.

1. Centralized Discovery for Public Sector Software

If you are a CTO or architect in a public body looking for software solutions, the Interoperable Europe portal will become the primary search engine for open-source tools developed by other EU entities. You will no longer need to navigate a fragmented landscape of national portals or individual agency websites. The catalogue will aggregate these resources, significantly reducing the time spent on sourcing and due diligence.

2. Free and Open Access

The "free of charge" mandate in Article 43(2) guarantees that access to this discovery layer is universal. This is particularly significant for SMEs and startups that may lack the resources to pay for proprietary software marketplaces or specialized search tools. It levels the playing field, allowing smaller players to compete for public contracts by leveraging the same pool of open-source innovations as larger incumbents.

3. Integrated Learning and Training

The strategic link to training mentioned in Recital 83 means that the catalogue will not just list software; it will facilitate adoption. For developers and implementers, this implies that when you discover a solution, you will likely find:

  • Documentation on how to integrate it with existing systems.
  • Links to training modules or certification paths.
  • Case studies from other public bodies that have successfully deployed the solution. This reduces the "last mile" problem of open-source adoption, where code exists but skills to use it do not.

4. Opportunities for Repository Owners

If you manage a national or institutional open-source repository, Article 43(3) offers a pathway to increased visibility. You can request to have your repository connected to the EU OSS Catalogue. If the Commission approves based on objective criteria, your software gains pan-European exposure. This could lead to cross-border adoption, new partnerships, and a higher return on investment for public software development.

5. Interoperability by Design

Because the catalogue is hosted on the Interoperable Europe portal, solutions listed there are implicitly aligned with the Interoperable Europe Act. This suggests a higher likelihood that listed software adheres to EU interoperability standards (e.g., data formats, APIs, security protocols). For architects, this reduces the risk of integration failures and simplifies the technical assessment of potential solutions.

Common misconceptions

"The EU OSS Catalogue will replace all national open-source repositories."

  • Reality: This is incorrect. Article 43(3) explicitly provides for a federated model. Existing repositories are not replaced; they are connected to the central catalogue. National bodies retain control over their own infrastructure while benefiting from the central discovery layer.

"All open-source software used in the EU must be listed in the catalogue."

  • Reality: The obligation is specific. Article 42 applies only to software developed by or for Union entities and public sector bodies that they voluntarily decide to make available for reuse under an open-source license. It does not mandate that all public software be open-sourced, nor does it require private sector software to be listed unless the private entity chooses to connect its repository under Article 43(3).

"The catalogue is a code hosting service like GitHub or GitLab."

  • Reality: The catalogue is a discovery and access tool, not a code host. As clarified in the text, the actual code remains hosted in the connected repositories (national or institutional). The Interoperable Europe portal serves as the index and gateway, linking users to the source code and related resources.

"Access to the catalogue will require a subscription or fee."

  • Reality: Article 43(2) is unambiguous: the catalogue "shall be accessible electronically free of charge." There are no financial barriers to accessing the catalogue itself.

Related

This is general information about a draft EU regulation, not legal advice.